Short for retard card, an r-card is a metaphor for how certain people with various learning disabilities will exploit every possible loophole in order to gain an academic advantage over their classmates. They will even use their r-card status to get other students in trouble for disputes caused by their own general rudeness.

Note: This does not apply to people who actually NEED assistance due to learning disabilities, but ONLY to those who go out of their way to exploit the minor disability they have.

Ben never did his dishes, so Steve put them on his bed in order to teach him a lesson. Ben got in Steve's face and then called the campus security and got Steve in trouble by busting out his R-Card.